1. Field of the Invention
The invention relates to a camera which photographs an object field, and relates in particular to a camera with improved operability. It further relates to a camera that has the ability to display color information including color temperature and so forth of the object field. The invention further relates to a display apparatus for displaying color information in a camera and a colorimeter for measuring color information in order to take a picture of the object field with the appropriate color balance.
2. Description of Related Art
In color photography a revision use color filter for correction use is mounted to a camera in order to photograph an object field with a suitable color balance. The user uses a colorimeter and the colorimeter performs photometry on the color balance of entering light. The user then chooses a prescribed color filter from the color information obtained, including object field color temperature, light balancing factors, color compensating factors for photographing the object field with appropriate color balance and filter names corresponding to light balancing factors and color compensating factors, all of which allow the user to select the proper color filter.
However, it has previously been necessary to carry the colorimeter apart from the camera, in order to select a color filter for correction use.
Further, color film is made so as to maintain balance between each color component Y (yellow), M (magenta) and C (Cyan) when the appropriate exposure is provided for a light source below a designated color temperature. However, because the photographer will not always perform photography beneath the designated color temperature, the color balance is such that it can be adjusted by the filter which is attached to a front of the photographic lens.
With these types of filters, a light balancing filter (hereinafter referred to as LB filter), which converts the color temperature of the incident light of the camera to the color temperature which is appropriate for the type of film used, and a color compensating filter (hereinafter referred to as a CC filter), which performs adjustment of the color balance, are generally widely used. LB filters are provided in multiple types according to each photo-sensitive material, and CC filters are also provided as multiple types according to the photographic condition.
Because the camera of the prior art was not equipped with a function to measure the color temperature of the object field, the color temperature of the camera surroundings was measured by way of a colorimeter which was separate from the camera, and the most appropriate filter was selected according to the measurement result. For this reason, it was a very cumbersome process because one must always carry a colorimeter, and there was the fear that one might miss a rare shutter opportunity because photography preparation takes time.
In Japanese laid-open patent publication no. 6-242487 and Japanese laid-open patent publication no. 6-258694, a camera which provides a meter for color temperature is described. The camera described in these patents measures the color temperature based on the amount of light which the photometry element receives, and then displays the measurement result to the display device which is arranged on the top of the camera.
However, the camera described in the aforementioned 6-242487 displays only the color temperature, and does not provide the means to notify the photographer of the most appropriate filter for the displayed color temperature. For this reason, it was necessary for the photographer to select the filter himself according to the displayed color temperature. Additionally, in 6-258694, a camera which displays the filter name is described. However, in 6-258694, only the filter name is displayed, and the color temperature in not displayed. For this reason, the photographer is resigned to use only the filter which is displayed, and is unable to select a filter when desiring to obtain a photo of his preferred color.
Further, there are two types of films, a day light type film and a tungsten type film, each of which has different spectrum sensitivity characteristics. A day light type film is designed to produce the best color with a light source having a color temperature of about 5,500 K, while a tungsten type film is designed to produce the best color with a light source having a color temperature of about 3,200 K. Therefore, it is best to select a color filter corresponding to types of film having different color sensitivity.
A film type interchanging switch is provided for a colorimeter of the prior art and is used to select an appropriate color filter. Depending on the position of the film type interchanging switch, a different light balancing factor is obtained for each type of film (day light type or tungsten type). Hence, it became necessary to provide a filter type interchanging switch when the user desires to obtain a light balancing factor for both film types.